Low water levels in Bayou Lafourche forced the recent closure of the Bayou Lafourche Saltwater Control Structure above Lockport.
Last Thursday, after two days of talks with Lafourche Parish Water District #1 General Manager Dirk Barrios about the danger of low water conditions, the Lafourche Freshwater District decided to close the control structure to block the intrusion of high-salinity water into the parish’s drinking water.
“I was notified by Dirk that the water level in the bayou was critically low. He was concerned that with the low level and increased demand during the cold weather, intake pump cavitation could cause major problems,” said Freshwater District Executive Director Ben Malbrough.
Closing allowed the bayou water level above the structure to be raised significantly, which impacts water intakes for both Lafourche and Terrebonne parishes that are located above the control structure.
In August 2015, a project began to move the structure from its previous location in the Company Canal west of Lockport to its present location in Bayou Lafourche just south of the parish water district facility on Hwy. 308 in Lockport.
The structure relocation project was finished in November 2016, funded with a $4.125 million grant from the Coastal Impact Assistance Program.
The undertaking was part of a larger “Mississippi River Reintroduction into Bayou Lafourche Project”, an effort to increase flow capacity in Bayou Lafourche and benefiting the Terrebonne and Barataria Basins.
According to the Freshwater District web page, the structure when closed creates a reservoir in the bayou to the north of it. Gates within the structure allow some water to exit should the volume of that reservoir become too great.
Malbrough admitted that closure creates an “inconvenience” for those who navigate the bayou in that area, but hoped that the expected southerly winds over the next two days will allow for reopening.
“Usually the structure would be closed during increased water levels from the south. This was the first time it has been used in a low water ‘scenario’. We are looking to reopen on Thursday afternoon (Jan 11), when water levels are expected to stabilize on both sides of the structure,” said Malbrough.
Malbrough also noted that the Freshwater District is in the process of designing a new pump station at Donaldsonville which would help eliminate the need for closure of the saltwater barrier during future low water events.
“The situation which we faced this last week shows there’s a major need for that pump station which we are designing at triple the capacity--a rate of 1500 cubic feet per second of output,” he said.
Posted on Fri, January 12, 2018
by By Buster Avera Contributing Writer